#include<stdio.h>
//编写函数时，要保证功能的单一性 
int is_leap_year(int x){
	if(((x%4==0)&&(x%100!=0))||(x%400==0)){
		return 1;
	}
	else{
		return 0;
	}
}
int main(){
	int year=0;
	scanf("%d",&year);
	if(is_leap_year(year)){
		printf("%d\n",year);
	}
	return 0;	
}
